var destCity = function (paths) {
    for (let i = 0; i < paths.length; i++) {
        let flag = false
        for (let j = 0; j < paths.length; j++) {
            if (paths[i][1] === paths[j][0]) {
                flag = true
            }
        }
        if (!flag) {
            return paths[i][1]
        }
    }
}